OPTICAL TRANSMITTER AND METHOD FOR CONTROLLING BIAS OF OPTICAL MODULATOR

摘要

An optical transmitter includes: a mapper (31) that generates an electric field information signal from transmission data; a phase rotation circuit (33) that adds a phase rotation to the electric field information signal; a driver (13a-13d) that generates a driving signal from the electric field information signal to which the phase rotation is added; a modulator (15x, 15y) that generates a modulated optical signal according to the driving signal; and a controller (52) that controls a bias of the modulator according to a change in a carrier frequency of the modulated optical signal corresponding to the phase rotation that is added to the electric field information signal by the phase rotation circuit.